Camera modules in cost driven products (for example virtually all non-dedicated camera enabled consumer devices such as mobile phones or multimedia players/recorders) may implement the shutter mechanism in an electronic manner called “rolling shutter”. Unlike in classical camera devices, where sensor (or film) exposure may be controlled by a mechanical blind, electronic shutters may do so by activating and subsequently deactivating the respective sensor elements. While so-called synchronous shutters may activate and deactivate all light sensitive cells at the same time, rolling shutters may work by exposing the sensor row by row. Synchronous shutters may involve read out logic since the transfer to shadow memory may be desired to take place synchronously for all rows, thus increasing devices complexity and, in turn, cost.
Rolling shutter based solutions may spread the read-out time nearly over the whole frame cycle, thus allowing for relatively slow and small buffers on-chip. In practice rolling shutter based systems may therefore be the prevalent solution in all but the highest quality segments in consumer digital photography. The advantage of cost and complexity may come at a price though: Since the individual rows may be exposed to light at different points in time, fast moving objects (or camera movements/pans) may lead to noticeable artifacts.